Antennas are widely used in many applications to send and receive electro-magnetic signals, typically radio frequency (RF) signals, for communication purposes. There exist many different antenna designs and configurations that are intended for specific purposes or for particular operational parameters such as intended operational frequency, directionality, radiation pattern, efficiency or gain, and other parameters. For example, one consideration in antenna design is whether the antenna is intended for use at a fixed location, such as a television transmitter or a cell-phone tower, or whether it will be portable for temporary use in various different locations, such as for use with portable radios. If the antenna is intended to be portable, its design should facilitate compactness, transportability, and ease of set-up and break down.
As will be appreciated by those of skill in the art, antennas typically consist of a conductive material with electrons moving therein in accordance with an electrical signal causing the antenna to radiate a corresponding electromagnetic signal. Likewise, when an electromagnetic signal impinges upon the antenna, it will convert the electromagnetic signal to an electrical signal for further processing. It is also well known that antennas tend to transmit and receive signals optimally at specific frequencies and/or wavelengths that are often a function of the length of the antenna. For these reasons, it is necessary to tune the antenna and associated system to operate at different frequencies. Tuning can be accomplished in various ways, such as by adjusting the reactance, i.e., the inductance and/or capacitance, of the associated radio components, i.e., the transmitter and receiver, or by adjusting the length of the antenna. This type of tuning may be referred to as impedance matching whereby communication of the signals between the antenna and the transmission line to the other radio components is optimized.
Occasionally, the foregoing considerations may compete with each other. For instance, the complex design and interoperation of components needed to tune an antenna, especially by adjusting the antenna length, may compete with simplifying the antenna design to facilitate portability and ease of use. Accordingly, the present disclosure is intended to respond to the competing considerations of portability and tuning of an antenna.